Jordan l



UNITED STATES PATENT OFFICE. Y

VJORDAN L. MOTT, OF NEW YORK, N. Y.

REVOLVING CHAIR.

Specification of Letters Patent No. 4,156, dated August 20, 1845;

To all whom t may concern Be it known that I, J ORDAN L. Mo'r'r, of the Iron, which chairs are denominated by me the Eccentric Revolving Pivot-Chairs and I do hereby declare that the following is a full and exact description thereof.

The chairs which I am about to describe I have constructed principally to be used in schools, in which application of them they present some special advantages, as when fixed to the floor, their structure and position, in relationship to the writing desks, allow of a very ready occupation of, and removal from, the seat wit-hout any sacrifice of space, and with comfort to the occupant.

My chair has its seat, with the back attached thereto, placed on a pivot upon which it may revolveV horizontally; and my imy provement consists'in the so placing of said pivot, as that it be situated as nearly as may be, under the center of gravity of the body of the person occupying the seat. I am well aware that the placing of a seat upon a pivot is not a new device, but I am not aware, nor do I believe, that the proper situation of such pivot has heretofore been determined ,upon any ascertained principle of utility.

In my first experiments on this subject, I took the width of the seat from front to back as my guide in placing the pivot, but it soon appeared that this was no guide in fact, as the` addition, or abstraction, of an inch or two on the front of the seat has no influence whatever on the part of it ordinarily occupied by the sitter, this being governed by the back, and not, in any degree, by the front of the seat. The rule that I have adopted, after numerous trials, is to 'take the ordinary width of the seat, `from side to side, and

dividing this into ve parts, to place'the pivot in the middle between the two sides, and at the distance of two of these parts, or

at nearly that distance, from the back; and

it has been found that when so placed, the center of gravity of a person of ordinary size, when the back of the person touches the back cf the chair, will be, as nearly as may be, over the pivot, and that such will be the case whether he sits upright, or takes his seat forward on the chair, and inclines his body back, so as to let it bear against the upper portion of its back.

It may here be observed that practice has determined what shall be the ordinary width for the seat of a chair for a grown person; and where chairs of the ordinary size are to be used this width governs the distance at which I place the pivot from the back; but in preparing chairs for children, in schools or elsewhere, the seats are made proportionately narrower from side to side, and differ in width so far as to adapt them to the use of classes of smaller and larger children; their proportionate height also varying.

In the accompanying drawings, Figure l is a perspective view of my chair as made for the use of schools, and Fig. 2, a vertical sect-ion of the same from front to back.

Of these I have actually constructed live different sizes, adapted to children from four to sixteen years of age, but all made on the same general principle; these chairs vary in the height of the seat from ten to seventeen and a half inches. The support, A, which performs the office of legs, I have preferred, for school use, to make bell shaped; and these are screwed to the floor by screws passing through their flaring edges. The steadiness with which these chairs stand on their narrow bases, before being fixed tothe ioor, and when the seat is occupied, and

made to revolve, is a circumstance specially noticeable, and evincing the correctness of the principle of construction. Instead of the bell-shaped bottom, I sometimes use a tripod, as shown in Figs. 3, 4c, 5 and 6.

In'Fig. 7, two of the chairs are seen standing in front of a desk; these are to be so placed as that when the backs are turned toward the desk they will just clear it. In taking a seat, they are necessarily turned partially round, say one fourth of a circle, as it would be scarcely possible to do so otherwise. When again turned so as to carry the knees under the desk, the body may be said to be forced into that position that is most favorable to health,"while there is ample room for ease and comfort.

The seat, B, of this chair, I generally make of wood, and the back, C, of cast iron, uniting the two lower ends, C', of the back by a plate C cast in one piece with them, on which the wooden bottom rests, and to which it is secured by means of screws. On the and project-ing up through the disk7 a, constitutes the revolving joint, there being a screw nut at the upper end of the pin to keep the parts in place.

Having thus fully described the lnature of my improvement in the eccentric revolving pivot chair, what I claim as new is- The placing of the pvot, or pin, upon which the seat revolves, at an equal dislo tance from the two Sides of the seat, and at two fifths, or nearly so, of that distance from the back of the chair, as set forth; or at a point so near to-that distance as shall be substantially the same n the result 'of its action.

JORDAN L. MoTT.

Vitnesses AUGUSTUS F. VVEEKES, LAW. S. MoTT. 

